In my prior U.S. patent application, Ser. No. 866,595, filed Jan. 3, 1978, I disclosed a plunger valve nozzle which, particularly for small engines, embodied several important advantages over then known nozzles of this type such as represented by my prior U.S. Pat. No. 3,982,693. Included among those advantages as set forth in said prior patent application were the use of a direct acting piston type plunger valve, a constant diameter bore nozzle body and axial pressure fluid flow from the spring chamber to the plunger valve.